Cushioning device for liquid-conveying pipes.



T. J. FOX. CUSHIONING 111111101: FOR LIQUID CONVEYING PIPES.

APPLIOATION FILED MAR. 19 1912.

Patented Mar.18,1913.

wi twmoco UNITED s'rArEs PATENT OFFICE.

THOMAS J. Fox, 0F MEMl-HIS, TENNESSEE, ASSIGNOR 'ro J. A. BILLIONS, 0E SHELBY,

rENNEssEE.

cusnronmo DEVICE FOR LIQUID-CONVEYING PIPES.

Specification of Letters Patent. Patented M31. 18, 1913- Application filed March 19, 1912. Serial No. 684,866,

To all whom, it may concern:

Be it known that I, THOMAS J. Fox, a citizen of the United States, residing at Memphis, in the county of Shelby and State of .Tennessee, have invented certain new and useful Improvements in Cushioning Devices for Liquid-Conveying Pipes, of which the following is a specification, reference being had therein to the accompanying drawing.

The invention relates to cushioning attachments for pipes in which sudden changes of liquid pressure occur from time to time, and the devices are particularl intended for use in connection with arge pipes and where it is important that the apparatus should always be ready for operation although infrequently actuated.

In the accompanying drawings, Figure 1 is an axial section of the apparatus. Fig. 2 is a section on the line 22, Fig. 1. Fig. 3 is a section on the line 3-3, Fig. 1.

In these figures, A represents the end portion of a pipe, such for exampleas a water main, provided with an openmgpreferably not less in area than the cross sectional area of the interior of the pipe.

B represents a heavy cylinder bolted to the pipe and registering internally with the opening therein. It is provided at its upper end with an annular cap C which is pressed down upon wedge-like packing R by bolts D. Within the upper portion of this cylinder fits and slides an upwardly closed cylinder E having a marginal flange E which normally rests upon the cap C. From the cap C rise rods F which carry at their upper ends a cup-like disk G provided with a central threaded adjusting bolt i which may be fixed against rotation by a lock-nut G Upon the flange E rests a spring H the upper end of which abuts a cu or disk H fitting over and held in ahnement by the disk Grand the lower nonthreaded end of the bolt a shoulder of which presses upon the lower disk and governs its position and hence the compression or tension of the spring. Upon the rods F are sleeres F provided with lateral projections F which by sliding and rotating the sleeves maybe thrown into and out of the path of the flange E at any point above or below the same, to lock it against ascending or descending, for example, when adjustments or repairs are being made, the sleeves themselves being fixed to the rods by setscrews F Within the cylinder E works a plunger made up of oppositely turned telescoping cups I, K which areadjustable in respect to the space between the bottoms of the cups by means of a plunger rod L sliding in a packed bearing in the top of the cylinder F and havlng its lower end portion provided with fight hand and left hand threads to engage the cups, respectively. The cylindrical wall of the lower cup is provided with external circumferential grooves M into which, respectively, passa es M lead from the interior of the cup, an around the grooved portion, between a marginal flange and the edge of the upper cup, are placed wedge-like packing rings M The interior of the plunger being filled with oil, proper rotation of the plunger rod will tend to compress the packing and force it outward and will at the same time apply strong pressure to the oil and force it out through the packing. Between this plunger and the top of the cylinder E is compressed a spring C011 L materially lighter than the coil H above.

In the lower portion of the cylinder B and ust above the pipe A' is a free plunger head N having the usual flexible marginal flange which is pressed outward by the water below the plunger. The space between this plunger and the plunger I, K above is filled with heavy oil or flowing grease'O which remains immovable so, long as the normal water pressure below is just equal to the resistance of the springs above, but whichmoves upward whenever the water pressure is materially increased and downward again when that pressure falls. A'sthe lower spring ofiers normally less resistance than the'one above, the first effect of a water hammer blow is to compress this spring instantly and without overcoming inertia of any heavy parts, the grease bein in this" respect a part of the hammering liquid column. When the spring below no longer yields readily, the cylinder E rises, compressing the sprin above. Thus the hammer blow meets IGSlStflIlCQWhlCll rapidly increases from zero to a maximum, and meantime the water column advances while being arrested through a distance-depending upon the length originally determined upon for the apparatus.-

' i It is of moment that no water should escape past the moving devices; and the packings mentioned, the oil forced through the packing, and the grease all tend to prevent such action. For like reasons, I provide aflange Q, in'the lower portion of the cylinder B and above the path of the plunger head N. This flange beingdownwardly inclined, should water by-any means follow up the side of the cylinder, it would hardly continue its course beyond this flange.

It is to be noted that the air trapped in the cylinder E may aid in cushioning, but in this large apparatus little reliance is placed upon such action, and in fact wlthout the spring this portion of the apparatus would against the water soon be inoperative because the air being always under pressure, wouldsoon disappear.

In use, the rods F and the upper spring are usually above the surface of the ground so that the sleeves F may readily be set to hold the lower portion of the device securely pressure it the spring above be removed.

What I claim is:

1, The combination with a liquid convey of said cylinder, .a hollow plunger provided with lateral oil apertures and located at some distance 'from'sald plunger head, to

form a grease chamber between the two, and

means for at will varying the internal capacity of the hollow plunger. 3. The combination with a water main, of

a cylinder communicating with the main, a 'plunger head in the lower portion of the cylinder, an upwardly closed cylinder slid- 4 ing in the upper part of the cylinder first mentioned, a spring resisting the upward movement of'the second cylinder, a two-part oil-containing plunger working in the second cylinder and provided with circumferential packing and with apertures leading from within to said packing, a spring resisting the upward movement of said plunger, and means operable from above said cylinders to vary the tension of the last mentioned spring and to force oil through said apertures.

4. The combination with an open cylinder adapted to have one end fixed to and in communication with a liquid conveying pipe and provided at some distance from that end with an internal, downwardly turned, an! nular flange, of a plunger working in sai cylinder near said end, a second cylindew fitting and sliding in the outer portion of the first, an oil filled, laterally perforated plunger working in the second cylinder,

means for applying pressure to the oil in the plunger, a spring resisting the outward movement of the hollow plunger, and a sec- 0nd spring, of different resistance, 0 posing the outward movement of the secon cylinder, the space between the two plunge s being filled with greasy material flowing nder pressure.

5. The combination with an open cylinder adapted to have one end fixed in communication with a liquid conveying pipe, of a plunger working in said cylinder near said end, a second downwardly open cylinder sliding in the first, a plunger working in the second cylinder, a'spring carried by the second cylinder and resisting outward movement of the plunger therein, a spring acting againstl the outer end of the second cylinder, rods '3 extending outward from the first cyli'nder alongside the spring last mentioned, and adjustable stops carried upon said rods and adapted to-be swung into and out of the path of the outwardly moving second cysliinderi In testimony whereof I afiix my gnature in presence of two witnesses. 1

THOMAS J. FOX.

Witnesses:

J NO. P. BULLINGTON, T. C Loonnr. 

